Liquid crystal display (LCD) is a flat panel display device using the characteristics of the liquid crystal materials to display images which has many advantages, such as lightweight, low driving voltage and low power consumption, and has becoming the mainstream products in the whole consumer market.
Liquid crystal panel is the most important component of the LCD which contains a thin film transistor (TFT) array substrate and a color filter (CF) substrate that are laminated in vacuum, a liquid-crystal layer and alignment films filled between them. The alignment films are equipped on the TFT array substrate and/or CF substrate to control the predetermined initial arrangement of liquid crystal molecules of the liquid-crystal layer in order to influence the performance of the liquid crystal panel.
The manufacturing process of liquid crystal panels is mainly divided into three parts: array process, cell process and module assembly process. A TFT substrate and a CF substrate are provided in the array process, and the TFT substrate and CF substrate are laminated in vacuum while a liquid-crystal layer and alignment films filled between them in the cell process. The module assembly process is a production process in which a liquid crystal cell obtained after the cell process is assembled with various components such as backlight plate, circuit, frame, etc.
The cell process generally is: an alignment film is formed on the TFT substrate and CF substrate respectively, then liquid crystal compositions are dropped on the substrates by one-drop filling technology (ODF), and lastly, the two substrates are laminated in vacuum followed by UV curing process. One method to form alignment films is to coat alignment materials on the inner surface of the TFT substrate and CF substrate while manufacturing the TFT substrate and CF substrate. In this method, static electricity and impurities carried on a brush for coating are generated easily to cause damages to a liquid crystal panel. Meanwhile, special devices and time required for forming alignment films and high costs of alignment materials remind the manufacturing costs of liquid crystal panels high. Moreover, a MURA phenomenon is caused due to different effects of liquid crystal molecules and liquid crystal reactive monomers on alignment films contained in liquid crystal compositions.
As a result, it is necessary to provide a new monomer to solve the problems existing in the conventional technologies.